This invention concerns underwater lighting, including for photography, and in particular a compact and powerful underwater light that is easily switched from one mode to another. In one aspect the device is a focus light or imaging light for underwater diving, used to locate photography subjects in darkness or very low light situations. The device of the invention allows focusing on a subject using a camera's auto focusing feature, then moving in on a subject without disturbing the subject. In another aspect the device is a flood light that toggles to a spot light, switching modes in the same way as the imaging light. The device may also include a laser pointer.
Focusing lights for underwater diving are well known. Used in low light situations such as night diving, the focusing light, typically mounted on an underwater camera housing, is used to locate and then focus on a subject for photography, taking advantage of the auto focus feature on a still camera.
An imaging light can also be used for taking video of underwater subjects. When used as a video light the typical arrangement is with two lights separated at some distance, both focused on the subject. When used as a focus light, the typical arrangement is mounted on the top of the photo housing where the user has quick access and the light points in the same direction of the camera. In photography applications the actual photo is taken using powerful strobes. The focus light insures the camera is properly focused prior to the actual shot when the strobes fire in concert with the camera shutter. The strobes overpower the focus light, which doesn't interfere with the shot even if left on.
A problem is that the white light of the focus light tends to cause fish or other animal subjects to react, quickly escaping before being captured in a photograph. The diver is thus unable to move in on the subject with the light before taking the picture.
It is known that red light generally does not have the same effect on the seagoing creatures, who often do not see or react to red light due to the filtering effect of the water which over 30 feet in depth typically filters out most red and yellow wavelengths. Consequently the fish or other animals do not react to red light. For this reason, one solution previously provided on focus lights has been a red flip-down filter that can be brought down over the front lens or window of the white light.
Red light has the additional advantage that it tends to attract fewer small creatures that are often attracted to white light and tend to swarm around white lights, interfering with the shot. This causes the photographer to turn lights off completely and wait until the swarming creatures, often the size of small flies or gnats, leave the area before turning the lights back on just before taking the shot.
Dive lights are often used by divers for viewing scenes and objects, whether or not in support of underwater photography. To illuminate a large scene a diver will need a flood light, while looking deep into a cave, or signaling a companion, usually requires a spot beam. Until this invention there has been no compact, high-power unitary device that is quickly toggled between flood beam and spot beam.
A further desire of divers is to be able to point out specific objects to other divers with a high degree of accuracy, such as identifying a small animal of interest. Recently, divers have begun using green lasers for this purpose; green lasers perform much better than common red lasers because they are much brighter to start with, and red light is rapidly absorbed as it travels through seawater. However, no lighting devices currently known provide the user the ability to illuminate a scene with spot or flood light, and switch to a laser pointer with the same device, or vice versa. Also, no device exists in which the white spot beam is combined with a laser pointer positioned in the center (or approximately at center) of the white spot beam. Even a tight spot beam below 10° in angle casts a wide enough spot at a distance that as a pointer it lacks the precision of a laser which can produce a point of light on a distant subject.
There is a need for a more efficient, compact, convenient, and high-powered underwater lighting device for conveniently switching between one form of light projection to another, while also preferably allowing for adjustment of light level, along with other desirable features.